Although most patients report wanting their physicians to address the religious aspects of their lives, most physicians do not initiate questions concerning religion with their patients. Although religion plays a major role in every aspect of the life of a Muslim, most of the data on the role of religion in health have been conducted in populations that are predominantly non-Muslim. The objectives of this study were to assess Muslim physicians' beliefs and behaviours regarding religious discussions in clinical practice and to understand the factors that facilitate or impede discussion of religion in clinical settings. The study is based on a cross-sectional survey. Muslim physicians working in a tertiary care hospital in Saudi Arabia were invited to complete a questionnaire that included demographic data; intrinsic level of religiosity; beliefs about the impact of religion on health; and observations, attitudes, behaviours, and barriers to attending to patients' religious needs. Out of 225 physicians, 91% agreed that religion had a positive influence on health, but 62.2% thought that religion could lead to the refusal of medically indicated therapy. Over half of the physicians queried never asked about religious issues. Family physicians were more likely to initiate religious discussions, and physicians with high intrinsic religiosity were more likely to share their own religious views. Residents and staff physicians tended to avoid such discussions. The study results highlight the fact that many physicians do not address patients' religious issues and that there is a need to clarify ethically sound means by which to address such needs in Islamic countries. Medical institutions should work to improve the capacity of medical personnel to appropriately address religious issues. The training of clinical religious advisors is a promising solution to this dilemma.